Propelling mechanism for vehicles.



No. 642,410. Patented Ian. 30, I900. C. YOUNG.

PBOPELLING MECHANISM FOR VEHICLES.

(Application filed Mar. 25, 1898.)

2 Shoots-Sheet l.

(N! Mnde1.)

No. 642,4l0.

' Patnted Jan. 30, I900. c. vouus.

PRUPELLING MECHANISM FOR VEHICLES.

(Apvlicntion filed Mar. 28, 1898.)

2 Sheets-sheaf 2.

(No Model.)

us PETERS ca. FNOTO-L|THO-, WASHINGTON, o. c.

NITED STATES PATENT FFICE.

CARL YOUNG, OF CHICAGO, ILLINOIS.

SPECIFICATION forming part of Letters Patent No. 642,410, dated January30, 1900.

Application filed March 28, 1898. Serial No. 675,387. (No model.)

.To ctZZ whom it may concern:

Be it known that I, CARL YOUNG, a citizen of the United States, residingat Chicago, in the county of Cook and State of Illinois, have inventedcertain new and useful Improvements in Propelling Mechanism forVehicles, of which the following is a specification.

My invention relates to the propelling mechanism of vehicles, such asbicycles of the type having a main crank, with an auxiliary crankrevolubly attached to the end of the main crank and adapted to berevolved, so as to lengthen the crank as a whole during the portion ofits movement through which power is applied to it to propel the vehicle;and it has for its object to produce certain improvements in theconstruction of the parts of such a machine whereby it may be renderedmore efficient.

In the drawings I have shown the propelling mechanism of a bicycle whichembodies the essential ideas of my present invention and which I willnow describe in detail.

Figure 1 is an elevation of the hanger portion of the frame of a bicycleand the propelling mechanism mounted therein. Fig. 2 is a sectionthrough the crank-shaft and associated parts, taken on line 2 2 of Fig.4.. Fig. 3 is a sectional view of the extremity of the main crank,showing the mounting of the auxiliary crank, such section beingta-ken online 3 3 of Fig. 5. Fig. 4 is a sectional view of the hanger and themounting mechanism of the shaft. Fig. 5 is a section on line 5 5 of Fig.3.

The same parts are indicated by the same letters in all the figures.

The crankAis keyed in the usual manner to the shaft B, supported in thehanger formed by the juncture of the frame-pieces C, carrying thesprocket-wheel D, which drives the main wheel of the bicycle in theusual manner. Instead, however, of having the pedal mounted in the usualmanner at the extremity of the crank I provide the auxiliary crank E,which is revolubly mounted at the extremity of the main crank andcarries at its extremity E the pedal to which the power is applied.

It will be seen that the pedal may be revolved through a circumferenceabout its axis at or near the extremity of the main crank and when sorevolved will be extended outward beyond the extremity of the main crankthrough one portion of its movement and through another portion will beextended inward toward the shaft. This revolution may be automaticallyregulated so as practically to lengthen the crank as a whole during thedownward portion of the stroke through which the poweris applied and toshorten it during the remaining portion, so that the foot of the riderwill move through substantially the same distance as though the pedalwere upon the end of the main crank; but the length of the effectivecrank or lever is increased while the power is being applied. This iseffected as follows: The auxiliary crank is mounted upon the shaft E,which carries the sprocket- Wheel F, with which it may be formedintegral, as shown. This sprocket-wheel F is connected by chain F withsprocket F, attached to the main frame of the bicycle concentric withthe shaft B, so that as the crank A revolves the sprocket-Wheel F andthe shaft E and pedal- -crank E will turn relative to the strap or bandA of the crank A, in which they are j ournaled. Now if the sprocket Fwere rigid with the main frame it is evident that the pedal would movethrough the circumference of a circle having the same diameter as thecircumfer ence through which the shaft E would move, but having itscenter forward of the shaft B by the length of the auxiliary crank. Ihave, however, provided a mechanism which somewhat alters this path, theaim being to have the auxiliary crank extended to its maximum positionthrough a considerable portion of the downward stroke, as from a to 5,instead of at only one point in its stroke, thereby in creasing theefficiency of the device. This is accomplished by havingthesprocketFspringmounted.

I will describe more in detail the mounting of the parts as seen inFigs. 2 and 4. The pieces C are bracketed to the tubes C of themainframe of the bicycle in the manner shown in Fig. 1 and form asupport for the mechanism which I am now describing. C is a hub orflange into which the ends of these bracketed'pieces are united. Thesprocket F fits loosely upon the outer surface of this flange. One end Gof a coil-spring G is attached to the flange C and the other end G ofsuch spring is attached to the sprocket F. It will thus be seen that thesprocket F is attached to the stationary flange C but it is attachedthrough the medium of the spring G, so that it maybe turned through aportion of a revolution, 01', in other words, it has a yieldingattachment to the frame of the bi cycle.

Of course all the parts which revolve are provided with ball-bearings.The sprocketwheel D has the balls H between it and the cup 11 and ballsH between it and the cup K. The balls K rest between this cup K and thecone L.

I will now describe more in detail the mounting of the auxiliary crank.

The main crank A ends in the strap or band A, and the shaft E of theauxiliary crank passes through and is mounted within such strap or band.This shaft E is formed integral with the sprocket wheel F and is formedwith a square portion, over which the crank E, having a'hole tocorrespond in shape with such portion of the shaft, is slipped. The nutE may be screw-threaded upon the ex tremit-yof theshaft to hold theauxiliary crank in place. This shaft E is threaded at its centralportion E to receive what I term the clutch-hub E which is screwedthereon and keyed thereto at E. This clutclrhub is loose within thestrap A and is supported in ball-bearings by the cones E". In theperimeter of this clutch-hub are the pockets E shaped as shown, andwithin these pockets are balls E held at the point of contact by thesprings E The operation of myinvention may be described as follows: Asshown in Fig. 1, the parts are in the position which they will be in atthe central portion of the downward stroke, the power being applied tothe pedal at the point E by the foot of the rider. Commencing at thispoint, we will follow the operation through one cycle. The clutchmechanism between the shaft of the auxiliary crank and. the strap withinwhich it is mounted is now locked, and the auxiliary crank is thereforerigid with the main crank, and the whole acts as if it were one integrallever. Then the point I) is reached in the movement of the pedal andcrank, the pressure of the foot vof the rider is relaxed or removed, andthe action of the coil-spring will thereupon turn the sprocket F backinto its normal posit-ion. This operation will turn the shaft carryingthe auxiliary crank back, so that the point IE will lie in thecircumference X, which circumference represents the path the point Ewould follow throughout its revolution if it were not for the action ofthe coil-spring.

It will travel along this circumference until a point which I havedesignated on the drawings as a is reached, such point being the pointat which the rider begins to apply power to the pedal. The sprocket Fwill be turned against the action of the spring until (when the partsare adjusted properly) the auxil-, iary' crank is extended in line withthe main crank, as shown in Fig. 1, whereupon the operation of theclutch makes the connection between the two cranks rigid, and suchrigidity is maintained so long as the power is applied.

What I claim as new, an by Letters Patent, is-

1. In a propelling mechanismfor avehicle, the driving-shaft, the cup Ksurrounding the shaft, and the bracketed portions secured to desire tosecure the frame of the vehicle at their outer ends and having theirinner ends provided with hubs or flanges which surround the cups,combined with the sprocket-wheel F placed upon the hub or flange, anintermediate spring having one end connected to the sprocket and theother to the hubor flange, and a crank mechanism which is operated fromsaid sprocket, substantially as set forth.

2. In a propelling mechanism for a vehicle, the main crank provided witha strap or band upon its outer end, a sprocket F formed integral withits shaft, and the auxiliary crank rigidly connected to the outer end ofthe shaft, combined with a clutch-hub rigidly secured to the shaft andloose within the strap or band, suitable ball-bearin gs, andclutch-balls which engage with the strap or band, achain which passesaround the said sprocket, the sprocket-wheel F which is yieldablymounted on the frame and around which the chain passes, and thesprocket-wheel D which is mounted upon the driving-shaft and is keyed.thereto, substantially as shown.

In a propelling mechanism fora vehicle, the bracketed portion 0 providedwith the flange 0 upon its inner end, the cup placed inside of theflange'C the balls H, H, K, the cone L, and the sprocket-wheel D keyedto the shaft combined with the sprocket-wheel F yieldingly mounted uponthe flange C the spring which unites the sprocket-wheel and the flange Cand a mechanism mounted upon the crank, and which is operated by thesprocket F, substantially as described.

Chicago, Illinois, March 18, 1898.

CARL YOUNG. itnesses:

- FRANCIS M. IRELAND,

M. THOMPSON.

